A Production is mainly defined by a product, a BOM, a location, a quantity and
two lists of moves:

Inputs

The moves between the storage location and the production location (as
defined on the warehouse) for products used for production.

Outputs

The moves between the production location and the storage location for
products produced.

The production can be in one of this states:

Request

The production is requested by the system.

Draft

Input and output moves are in draft.

Waiting

The production is waiting for action and all moves are still in draft.

Assigned

The input moves are assigned.

Running

The input moves are in state done.

Done

The output moves are in state done.

Cancel

All moves are cancelled.

The cost of the production is computed with the sum of the cost price of all
incoming products. If a product is selected, it will have the cost as unit
price. The production verify that all the cost is spread on the unit price of
output moves.